Any talk about Serena Williams' body transformation is going in one ear and out the other ... 'cause the tennis legend tells TMZ Sports she's feeling like a million bucks!!
Williams, 43, has been sharing photos of her new slimmed-down physique on social media over the past few months ... which sparked plenty of reactions -- both positive and negative.
Williams doesn't seem to care one bit either way ... as she brushed off the critics outside Hotel Fouquet in New York City this week.